US6384947B1 - Two path digital wavelength stabilization - Google Patents
Two path digital wavelength stabilization Download PDFInfo
- Publication number
- US6384947B1 US6384947B1 US09/265,291 US26529199A US6384947B1 US 6384947 B1 US6384947 B1 US 6384947B1 US 26529199 A US26529199 A US 26529199A US 6384947 B1 US6384947 B1 US 6384947B1
- Authority
- US
- United States
- Prior art keywords
- signal
- path
- laser
- digital
- optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/572—Wavelength control
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/501—Structural aspects
- H04B10/506—Multiwavelength transmitters
Definitions
- the present invention relates to a novel and useful method for stabilizing the wavelength of a laser source.
- Laser sources are widely used in wavelength division multiplexed systems. In wavelength division multiplexed systems, it is important that the wavelength used is very stable. Although lasers are inherently very stable, increased stabilization of a laser's wavelength becomes crucial as systems migrate to dense wavelength division multiplexing (DWDM) types. In DWDM systems, many wavelengths are placed on a single fiber to increase system capacity. Currently the spacing in DWDM systems between frequencies is around 100 GHz and can be handled by traditional laser stabilization methods. However, as technology moves toward frequency spacings of 25-50 GHz or less, increased stabilization will be required to prevent interference between wavelengths as the spacings become closer and closer.
- DWDM dense wavelength division multiplexing
- the wavelength or equivalently the optical frequency of a laser is compared to a stable reference element.
- One method is to use an optical filter as a reference element.
- the output of the laser is split and part of the beam is passed through an optical filter to create an optical signal which is a function of wavelength or frequency and optical power (hereinafter “the optical filtered path”).
- the optical filtered path is then processed, assuming that a change in signal amplitude corresponds to a change in frequency, and a signal is generated which is fed back to the laser to stabilize the laser's wavelength.
- a change in signal amplitude at the output of the filter could be the result of a change in the power output of the laser rather than a change in the laser's frequency.
- Another method of stabilizing a laser is to pass a slightly diverging beam of light, obtained by splitting the output of the laser source, through a filter at different angles of inclination as shown in FIG. 1 .
- the two photo-detectors, P 1 and P 2 act as apertures and capture a different portion of the light emitted by the divergent source. This produces two different spectral responses, offset in wavelength according to their angular difference with respect to the filter. Since P 1 captures a portion of the emitted light which passed through the filter at a higher tilt angle than that captured by P 2 , it's response will peak at a slightly lower wavelength than P 2 as depicted in FIG. 2 .
- the filter and alignment parameter are chosen so that the wavelength offset between the two responses is roughly equal to their effective bandwidths.
- wavelength or frequency drift can be introduced by the aging or temperature dependence of the laser itself, or by the aging or temperature dependence of the optical reference filter, the optical detectors, or the stabilization electronics.
- manufacturing variations of system components can result in varying wavelengths from system to system.
- Existing systems are unable to adequately compensate for the multitude of variables that can arise in a stabilization system when a very high level of stabilization is needed.
- the present invention provides an improved method for stabilizing the wavelength of a laser source.
- the invention accomplishes this objective by using an optical filter, dual optical paths, analog and digital conversion, and a microcontroller.
- wavelength stabilization of a laser is accomplished via a laser, optical couplers, an optical filter, optical detectors, current-to-voltage converters, amplifiers, analog-to-digital converters, a microcontroller, and a digital-to-analog converter.
- a laser generates a signal which is carried by a fiber optic cable.
- Two separate paths are created from the fiber optic cable via photo-couplers.
- the first path is an optical filtered path which passes through an optical filter.
- the second path is a power reference path used for normalization. Since the optical filtered path contains an optical filter, it provides a signal the power of which is a function of wavelength as well as the optical power output of the laser.
- the power reference path is unfiltered so as to provide a signal the power of which is a function only of the optical power output of the laser.
- a change in the output power of the optical filtered path should primarily indicate a frequency change of the laser. However, the change may be due to a change in the optical power of the laser.
- the other components are used to provide electrical signals, convert the signals into a usable form, and manipulate the signals.
- Optical detectors are used to convert the optical signals from the optical filtered path and the power reference path to electrical signals.
- the electrical signals produced by the detectors are then converted from current to voltage, via current-to-voltage converters.
- the current-to-voltage converters may provide some pre-amplification to the signal or pre-amplification may be provided by other means.
- the signals from the converters are amplified, via amplifiers, to provide gain and prepare them for analog to digital conversion.
- the amplified signals are then converted from analog to digital by analog-to-digital converters to prepare them for processing by a microcontroller.
- the microcontroller then processes the signals in any manner desired using software code and generates an appropriate signal which is converted from digital to analog by a digital-to-analog converter for use in adjusting the laser's frequency.
- the microcontroller's processing can be accomplished by any of the following types of apparatus: microprocessor, processor, digital signal processor, computer, state machine, or essentially any digital processing circuit.
- the present invention adds greater flexibility to wavelength stabilization systems. For example, long integration times, which are impractical via traditional stabilization means because of unrealizable component values and physical size restrictions, level shifting or stabilization on either/or both positive and negative slopes, and accommodation of manufacturing variations in the optical filter, are all possible utilizing the present invention.
- FIG. 1 is a block diagram of a two-path wavelength stabilization system in accordance with the prior art
- FIG. 2 is a graph depicting signal amplitude vs. wavelength of the signals at the photo-detectors, P 1 and P 2 , in the circuit of FIG. 1;
- FIG. 3 is a block diagram of a two-path wavelength stabilization system in accordance with the present invention.
- FIG. 4 is a circuit diagram of an exemplary pre-amplifier and current-to-voltage converter for use in the circuit of FIG. 3;
- FIG. 5 is a graph of the voltage level in the optical filtered path prior to analog to digital conversion in accordance with the present invention.
- FIG. 6 is a graph of the voltage level in the power reference path prior to analog to digital conversion in accordance with the present invention.
- FIG. 7 is a graph depicting optical filter slope vs. signal-to-noise ratio of the overall circuit of FIG. 3;
- FIG. 8 is a graph depicting optical filter slope vs. total drift of the overall circuit of FIG. 3, assuming the required optical stability is 5 ppm.
- FIG. 3 illustrates the components of the present invention which include: a laser source 12 , an optical fiber 14 , photo couplers 16 and 18 , an optical filter 20 , photo detectors 22 and 24 , current-to-voltage converters 28 and 32 , amplifiers 34 and 36 , analog-to-digital converters 38 and 40 , microcontroller 50 , and digital-to-analog converter 49 .
- the components connected together, as depicted in FIG. 3 provide increased stabilization for a laser to be used in dense wavelength division multiplexing (DWDM) systems or similar systems where very stable laser frequencies are required.
- DWDM dense wavelength division multiplexing
- the output 13 from either the front face or the back face of the laser 12 produces a signal having a power P L which is placed on the fiber optic cable 14 .
- the initial signal on the fiber optic cable is then used to create two independent paths, the optical filtered path 101 and the power reference path 102 .
- the optical filtered path 101 and the power reference path 102 are created by placing photo-couplers 16 and 18 , respectively, on the fiber optic cable 14 carrying the signal from the laser 12 .
- the optical filtered path 101 is passed through an optical filter 20 to obtain a signal which is, at least partially, a function of wavelength or frequency, and becomes a reference element for frequency stabilization.
- the power reference path 102 does not pass through the optical filter 20 and provides a signal which is a function solely of the laser's optical power P L , and is eventually used for normalizing the optical filtered path 101 .
- each path passes through a photo-detector 22 or 24 , current-to-voltage converter 28 or 32 , amplifier 34 or 36 , and analog-to-digital converter 38 or 40 .
- the photo-detectors 22 and 24 transform the optical signal from each path into an electrical signal which is required as an input for electrical circuits.
- the photo-detectors 22 and 24 produce an electrical current which is a function of the optical signal strength.
- the conversion or responsivity of the photo-detectors 22 and 24 is, for example, roughly 1 ampere of electrical current for each watt of optical power. Assuming the optical power into the photo-detectors 22 and 24 is 1 ⁇ W, the initial electric current out of the photo-detectors 22 and 24 is in the neighborhood of 1 ⁇ A.
- the current-to-voltage converters 28 and 32 convert the output of the photo-detectors 22 and 24 from a signal represented by a current to one represented by a voltage and provide some pre-amplification.
- the conversion of the signal from current to voltage and the signal's pre-amplification is combined as depicted in FIG. 4 .
- a current signal, i in is amplified and transformed into a voltage signal, v out .
- the amplification and current to voltage transformation is accomplished by a transimpedance amplifier 60 created by using an inverting amplifier 62 with resistor 64 in a feedback loop. If a 100 k ⁇ resistor is used for feedback resistor 64 , the output voltage v out will be approximately the input current 10 ⁇ 6 A times the feedback resistance 100 k ⁇ , or about 0.1 V.
- the amplifiers 34 and 36 provide additional gain to the signal to condition the signal for the analog-to-digital converters 38 and 40 . If the amplifiers 34 and 36 provide a gain of 10 , the signals will be approximately 1 V as they enter the analog-to-digital converters.
- FIGS. 5 and 6 depict the signals on the optical filtered path and the power reference path, respectively, prior to entering the analog-to-digital converters 38 and 40 . As can be seen in the figures, at this point, the signals are DC voltages carrying some noise with the voltage of the optically filtered path 101 slightly lower than the voltage of the unfiltered path 102 . This example assumes that the components in the two paths are matched (which, of course, is not a requirement).
- the analog-to-digital converters 38 and 40 convert the input analog signals to digital signals.
- the resultant digital signals 42 and 44 are in a form which can be processed and manipulated by the microcontroller 50 .
- the digital signals 42 and 44 are then processed by the microcontroller 50 , which produces the output signal 48 .
- the microcontroller 50 numerically divides the optical filtered path digital signal 42 by the power reference path digital signal 44 to normalize the optical filtered path digital signal 42 , whereby a digital value which is a function solely of the lasers wavelength is derived.
- the microcontroller can then use the digital value representing the laser's wavelength to generate signal 48 .
- Signal 48 is then converted from digital to analog by digital-to-analog converter 49 to produce a laser adjustment signal 51 which can be used for adjusting the wavelength of the laser 12 .
- the processing by microcontroller 50 can be accomplished by any of the following types of apparatus: microprocessor, processor, digital signal processor, computer, state machine, or essentially any digital processing circuit.
- the signal 51 can be in any form desired for controlling the frequency of the laser 12 and can be modified by changes in the microcontroller's software code via remote input 46 .
- the signal 51 generated through the digital-to-analog converter 49 by the microcontroller 50 may be a current for adjusting the temperature of a thermoelectric cooler on which the laser 12 is mounted, or the microcontroller 50 may generate other appropriate signals either with or without digital to analog conversion depending on the method used to modify the frequency of the laser 12 .
- the present invention can use this two path digital wavelength stabilization method to achieve a level of wavelength stabilization that is impractical or impossible via analog means.
- improved stabilization can be achieved by identifying small variations in the laser's wavelength. Small wavelength variations can be masked by noise in the laser 12 and stabilization circuitry 10 .
- the normalized signal can be integrated over a period of time, with improved signal to noise ratios resulting from longer integration periods.
- Traditional analog systems are constrained by an RC (resistance and capacitance) time constant. In order to obtain long integration times, such as a month, a capacitor the size of a trash can would be required.
- the signals can be sampled over a period of minutes, days, months, or even years, depending on the amount of time required to obtain a desirable signal to noise ratio.
- the microcontroller can accomplish long integration times by storing signal values in memory or keeping a running total of averages digitally.
- the digital approach to wavelength stabilization allows for flexibility in choosing system components. Different types of filters with varying characteristics can be used for optical filter 20 by modifying software in the microcontroller 50 , without changing other system components. This allows for using inexpensive filters or incorporating new filter designs into stabilization circuit 10 . Also, photo-detectors 22 and 24 , current-to-voltage converters 28 and 32 , and amplifiers 34 and 35 can be chosen based on availability or cost with variations in their respective signal levels accommodated by software in the microcontroller 50 . For example, if the optical filtered path digital signal 42 was twice as big as the power reference path digital signal 44 , due to mismatched components, the microcontroller 50 could divide the optical filtered path 42 by two or multiply the power reference path 44 by two. Attempting system modifications such as this, although readily achievable with a microcontroller, would require almost completely redesigning a circuit to accomplish in an analog system.
- this method of wavelength stabilization allows for the use of components with high levels of manufacturing variations, permitting the use of less expensive components. Variations in system components can be accommodated by changing software code in the microcontroller 50 , either at the factory when the laser's frequency is originally set, or via remote input 46 at a later date.
- the microcontroller 50 software can numerically account for amplifier component variations resulting in digital signal levels that are too high or too low, filters with varying wavelength characteristics, and other types of system variations. Attempting similar flexibility in an analog system would require exhaustive design considerations.
- the wavelength stabilization system 10 offers vast improvements over traditional stabilization systems. As stated above, long integration times, which were previously impractical because of unrealizable component values, flexibility in choosing system components, and accommodation of manufacturing variations in the optical filter 20 and other components in the circuit 10 , are all easily achievable utilizing the digital stabilization system 10 .
- the flexibility gained by using the new stabilization system 10 is due to the ability to program the microcontroller 50 to perform many different functions on the digital inputs 42 and 44 with software using mathematical equations, versus attempting to use analog circuit components to accomplish the same type of functions in an analog system.
- the remote input 46 can be used to modify software code in the microcontroller 50 . For example, various control algorithms or normalization methods can be used or changed at will via code changes in the microcontroller 50 via remote input 46 .
- the invention relates to a two path digital optical wavelength stabilization method which uses a microcontroller.
- the required optical filter selectivity which depends on the signal to noise ratio and unwanted amplitude drift is considered.
- This digital method where the wavelength set points are set numerically has many advantages, including:
- the required optical frequency stability is given as ⁇ f s .
- the series input noise current as a function of the shunt noise voltage of the pre-amplifier 60 is calculated here in order to place all values in the form of an equivalent noise current.
- the input noise voltage is usually found in the product data sheet for the particular pre-amplifier chosen.
- An exemplary pre-amplifier 60 circuit is shown in FIG. 4 .
- i in 2 ⁇ 0 ⁇ ⁇ v in 2 ⁇ ⁇ Y in ⁇ 2 ⁇ ⁇ f ( 1 )
- a ⁇ ( f ) A ⁇ ⁇ ⁇ - j ⁇ ⁇ ( ⁇ ⁇ ⁇ t - ⁇ ) i + j ⁇ ⁇ f f ref ⁇ A ( 4 )
- BW noise bandwidth
- a graph Of v in 2 is given in a typical pre-amplifier data sheet.
- One potential pre-amplifier that can be used in accordance with the present invention is the LMC 660 manufactured by the National Semiconductor Corp. of Santa Clara, Calif., USA.
- the noise voltage curve shown in the data sheets for the LMC 660 is found to be approximated by
- the capacitance term is usually shown in a typical receiver noise analysis, but for the condition of long integration times or low noise bandwidth, the first term, the A/R F term, dominates.
- A/D converter quantization noise is addressed here following the analysis of J. G. Proakis and D. G. Manolakis, Digital Signal Processing pg 412, Macmillan Publishing Company ISBN 0-02-396815-X, incorporated herein by reference. A number of assumptions regarding the nature of the quantization noise are made, i.e. uncorrelated, uniformly distributed, stationary white noise, etc.
- Psig is the signal power
- Pnoise is the noise power
- b is the number of bits
- R is the range setting
- ⁇ sig is the rms signal amplitude.
- the overload noise or clipping is set to be negligible by way of the chosen range value and is ignored.
- An analog-to-digital converter is selected with an adequate number of bits sufficient to make the quantization noise trivial. This is verified in the spreadsheet described in the following section.
- Table 2 is a spreadsheet for calculating the overall signal to noise ratio seen by the microcontroller 50 .
- noise terms above dominate, but the various terms are included for completeness. They also serve as place holders to allow calculations over a wide range of future conditions. At present, the noise voltage dominates the other noise terms by a wide margin and is the place to focus attention should a reduction in noise be required beyond what can be achieved through averaging.
- the received optical power available to the stabilization circuit at photodetectors 22 or 24 is (initially) assumed to be ⁇ 29 dBm.
- Different time constants or noise bandwidths exist for the analog and digital signals.
- the time constant in the analog portion of the circuit is determined by component selection, and is limited by component availability.
- the digital time constant is bound by the available memory and the software code in the microcontroller 50 .
- the analog and digital time constants are combined on a sum of squares basis to get an overall time constant, although in practice the digital bandwidth will be set to dominate the analog bandwidth by a wide margin.
- the total analog noise current of the analog signal at the electronic noise bandwidth is first calculated.
- the total noise except for the quantization noise can then be calculated at the overall noise bandwidth.
- the quantization noise of the analog-to-digital converter 38 or 40 can be included to obtain the total noise, both analog and digital.
- the overall signal to noise ratio is then calculated using the signal current determined from the optical power.
- the electrical signal current is given in the usual manner for the optical filtered path 101 by
- V A/D 1 P L C 1 C(f)RR T G (13)
- C 1 is the optical path loss which includes the optical coupler 16
- C(f) is the optical filter 20 insertion loss
- R is the detector 22 responsivity
- R T is the feedback resistance 26 across the preamplifier 60
- G is the postamplifier 34 gain which includes all electrical path losses.
- C( ⁇ ) or C(f) can be used.
- the optical filter 20 response is given by C ⁇ ( f ) ⁇ ⁇ C ⁇ f ⁇ ⁇ ⁇ ⁇ f + C chi ( 14 )
- C(f) is the optical filter transmission response
- dC/df is the filter 20 slope objective
- ⁇ f is the frequency difference from the desired value at channel i
- C chi is the filter 20 insertion loss for channel i.
- path 102 the normalization path
- the noise is understood to be the noise after normalization.
- the maximum overall noise is determined assuming that the mean value of the optical frequency is constant (no aging) and the entire frequency stability specification can be allocated to the noise.
- the noise is assumed to be Gaussian with an equivalent optical standard deviation ⁇ f and a mean value ⁇ f.
- ⁇ f is assumed to be zero (no aging) and the entire optical frequency specification is allocated to the standard deviation. Therefore, ⁇ ⁇ ⁇ f s ⁇ f ⁇ ⁇ ( 16 )
- ⁇ n0 is the dimensionless allowable electrical standard deviation of the total noise distribution which in practice is dominated by the electrical noise (see Table 2).
- ⁇ f the allowable standard deviation as a function of frequency
- the signal to noise power ratio at channel 1 is given by
- Equation (22) gives the required normalized optical filter slope in terms of the frequency stability specification, ( ⁇ f s /f), and the equivalent signal to noise ratio at the optical detector output under the assumption of zero drift.
- the signal to noise ratio may be the overall value which includes electronic noise.
- a plot of equation (22) is shown in FIG. 7 where ⁇ is assumed to be 1.
- noise was ignored and the entire frequency stability specification was assigned to aging which includes changes in the optical path, optical couplers, optical filters, optical detectors, and all electronics to the microcontroller. In practice the aging of components are unknown and will require measurement.
Abstract
Description
TABLE 1 |
Noise Terms |
Term | Units |
BW | Hz | Noise Band Width |
Rf | Ohms | Feedback Resistance |
RIN | Ohms | Resistance at Input Node |
CIN | F | Capacitance at Input Node |
b | Number of Effective Bits in A/D Converter | |
R | V | Range Setting of A/D Converter |
R/σ | Range to Noise Ratio at A/D Converter Input | |
IC Noise | pA/✓Hz | LMC 660 Data Sheet ˜2E-4 |
Current | ||
Noise Voltage | V/✓Hz | LMC 660 Data Sheet, Obtain ˜2E-7/f{circumflex over ( )}0.35 |
Noise Current | A2 | (2E-7){(A/Rf + l/Rf + l/Ri)2*BW{circumflex over ( )}0.3/0.3 + |
From Noise | (2*II*C)2*BW{circumflex over ( )}2.3/2.3} | |
Voltage | ||
Thermal Noise | A2 | 4*k*T*BW/Rf |
Current | ||
Shot Noise | A2 | 4*e*l*BW |
Current | ||
Laser RIN | A2 | BW*l{circumflex over ( )}2*RIN |
Quantization | dB | 6.02*b + 16.81 − 20*LOG(R/σ) |
S/N | ||
TABLE 2 |
Noise Analysis |
NOISE ANALYSIS | Units |
Preamp Shunt Noise Voltage Calculated from | V/✓Hz | 2.000E−07 |
Data Sheet of Assumed Device | ||
Preamp Feedback Rx Value | Ohms | 1.000E+05 |
Effective Post Amp Gain Front End Output to | Linear | 10 |
A/D Input | ||
Effective Electronic BW | Hz | 1.000E+02 |
Numerical Sampling Frequency = | Sec | 2.000E+02 |
2*electronic BW | ||
Numerical Averaging Time | Sec | 1.2000E+02 |
Effective Numerical Noise BW (BW ˜1/T) | Hz | 8.333E−03 |
Effective Overall Noise BW, | Hz | 8.333E−03 |
Electronic & Numerical | ||
Temp | ° C. | 25 |
Temp | ° K. | 2.980E+02 |
Total Capacitance at Input Node | F | 1.000E−11 |
Assumed Optical Path Conditions | ||
Assumed CW Laser Power at Optical Feedback | dBm | −16.0 |
Circuit | ||
Assumed Optical Path (Loss), | dB | −13.0 |
Fiber/Coupler/Filter | ||
Received Average Optical Power | dBm | −29.0 |
Equivalent Signal Current | A | 1.257E−06 |
Assuming ETTA = 0.8 | ||
Equivalent Signal Current Squared | A2 | 1.581E−12 |
Calculate Total Elect Noise at Elect BW | ||
Assumed Laser RIN Value | /Hz | 1.000E−14 |
Post Amp Noise Figure Etc., Ignore | dB | 0.000E+00 |
Post Amp Noise Figure Etc., Ignore | Linear | 1.000E+00 |
Equivalent Preamp IC Noise Current Sq. at Input | A2 | 4.000E−30 |
Equivalent Preamp Noise Current Sq. | A2 | 5.309E−15 |
from Noise Voltage | ||
TH. RMS Noise Current Sq. at Detector | A2 | 1.645E−23 |
Shot Noise Current Sq. in Received | A2 | 4.028E−23 |
Optical Signal | ||
Laser Mean Sq. RIN Noise Current | A2 | 1.581E−24 |
Total Electronic Noise Current Sq. | A2 | 5.309E−15 |
S/N Power Ratio at Electrical BW, | dB | 25 |
Signal Path Only | ||
Calculate A/D Overload | ||
(Verifies Proper A/D Range) | ||
Set Value for A/D Range | V | 1.500E+00 |
Electronic RMS Noise Voltage at A/D Input | V | 0.0729 |
Electronic Signal Voltage/Noise Voltage | 17.2558 | |
at A/D Input | ||
Ratio of A/D Range to Noise Sigma | 20.5863 | |
(Ignore Aging and Drift) | ||
A/D Overload (# overload samples per # samples) | 3.65E−94 | |
Total Noise Current at PIN at | ||
Total BW, Excluding A/D Quant Noise | ||
Assumed Laser RIN Value | /Hz | 1.000E−14 |
Ignore other Noise, Post Amp Noise Figure Etc. | dB | 0.000E+00 |
Ignore other Noise, Post Amp Noise Figure Etc. | Linear | 1.000E+00 |
Equivalent Preamp IC Noise Current Sq. at Input | A2 | 3.333E−34 |
Equivalent Preamp Noise Current Sq. from | A2 | 3.172E−16 |
Noise Voltage | ||
TH. RMS Noise Current Sq. at Detector | A2 | 1.371E−27 |
Shot Noise Current Sq. in Received | A2 | 3.357E−27 |
Optical Signal | ||
Laser Mean Sq. RIN Noise Current | A2 | 1.317E−28 |
Total Noise Current Sq. | A2 | 3.172E−16 |
S/N Power Ratio at Total BW | Linear | 4.985E+03 |
S/N Power Ratio at Total BW | dB | 37 |
A/D Effects Included Below | ||
Chosen Number of Bits of A/D Converter | 10 | |
S/N of A/D Converter (Power Ratio) | dB | 75 |
S/N of A/D Converter (Power Ratio) | Linear | 118534 |
S/N Current Ratio Sq. after Digitization, | A2 | 4783 |
Including A/D Converter | ||
S/N Ratio After Digitization, | dB | 37 |
Including A/D Converter | ||
Claims (23)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/265,291 US6384947B1 (en) | 1999-03-09 | 1999-03-09 | Two path digital wavelength stabilization |
US09/451,079 US6545788B1 (en) | 1999-03-09 | 1999-11-30 | Multiple path digital wavelength stabilization |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/265,291 US6384947B1 (en) | 1999-03-09 | 1999-03-09 | Two path digital wavelength stabilization |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/451,079 Continuation-In-Part US6545788B1 (en) | 1999-03-09 | 1999-11-30 | Multiple path digital wavelength stabilization |
Publications (1)
Publication Number | Publication Date |
---|---|
US6384947B1 true US6384947B1 (en) | 2002-05-07 |
Family
ID=23009851
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/265,291 Expired - Lifetime US6384947B1 (en) | 1999-03-09 | 1999-03-09 | Two path digital wavelength stabilization |
Country Status (1)
Country | Link |
---|---|
US (1) | US6384947B1 (en) |
Cited By (43)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6469814B1 (en) * | 1998-11-09 | 2002-10-22 | Electronics And Telecommunications Research Institute | Apparatus and method for detecting channel information from WDM optical signal by using wavelength selective photo detector |
US6519068B1 (en) * | 1999-10-18 | 2003-02-11 | Agere Systems Inc. | Circuits and methods for achieving high signal-to-noise ratios and obtaining stabilized laser signals in dense wavelength division multiplexing systems |
US6545788B1 (en) * | 1999-03-09 | 2003-04-08 | Agere Systems, Inc. | Multiple path digital wavelength stabilization |
EP1458070A1 (en) | 2003-03-12 | 2004-09-15 | Agilent Technologies Inc. a Delaware Corporation | Optical wavelength control system |
CN100452580C (en) * | 2007-02-09 | 2009-01-14 | 中国科学院上海光学精密机械研究所 | Device for stabling semiconductor laser operation wavelength |
US7526422B1 (en) | 2001-11-13 | 2009-04-28 | Cypress Semiconductor Corporation | System and a method for checking lock-step consistency between an in circuit emulation and a microcontroller |
US7737724B2 (en) | 2007-04-17 | 2010-06-15 | Cypress Semiconductor Corporation | Universal digital block interconnection and channel routing |
US7761845B1 (en) | 2002-09-09 | 2010-07-20 | Cypress Semiconductor Corporation | Method for parameterizing a user module |
US7765095B1 (en) | 2000-10-26 | 2010-07-27 | Cypress Semiconductor Corporation | Conditional branching in an in-circuit emulation system |
US7770113B1 (en) | 2001-11-19 | 2010-08-03 | Cypress Semiconductor Corporation | System and method for dynamically generating a configuration datasheet |
US7774190B1 (en) | 2001-11-19 | 2010-08-10 | Cypress Semiconductor Corporation | Sleep and stall in an in-circuit emulation system |
US7825688B1 (en) | 2000-10-26 | 2010-11-02 | Cypress Semiconductor Corporation | Programmable microcontroller architecture(mixed analog/digital) |
US7844437B1 (en) | 2001-11-19 | 2010-11-30 | Cypress Semiconductor Corporation | System and method for performing next placements and pruning of disallowed placements for programming an integrated circuit |
US7893724B2 (en) | 2004-03-25 | 2011-02-22 | Cypress Semiconductor Corporation | Method and circuit for rapid alignment of signals |
US8026739B2 (en) | 2007-04-17 | 2011-09-27 | Cypress Semiconductor Corporation | System level interconnect with programmable switching |
US8040266B2 (en) | 2007-04-17 | 2011-10-18 | Cypress Semiconductor Corporation | Programmable sigma-delta analog-to-digital converter |
US8049569B1 (en) | 2007-09-05 | 2011-11-01 | Cypress Semiconductor Corporation | Circuit and method for improving the accuracy of a crystal-less oscillator having dual-frequency modes |
US8069405B1 (en) * | 2001-11-19 | 2011-11-29 | Cypress Semiconductor Corporation | User interface for efficiently browsing an electronic document using data-driven tabs |
US8067948B2 (en) | 2006-03-27 | 2011-11-29 | Cypress Semiconductor Corporation | Input/output multiplexer bus |
US8069436B2 (en) | 2004-08-13 | 2011-11-29 | Cypress Semiconductor Corporation | Providing hardware independence to automate code generation of processing device firmware |
US8069428B1 (en) | 2001-10-24 | 2011-11-29 | Cypress Semiconductor Corporation | Techniques for generating microcontroller configuration information |
US8078894B1 (en) | 2007-04-25 | 2011-12-13 | Cypress Semiconductor Corporation | Power management architecture, method and configuration system |
US8078970B1 (en) | 2001-11-09 | 2011-12-13 | Cypress Semiconductor Corporation | Graphical user interface with user-selectable list-box |
US8085067B1 (en) | 2005-12-21 | 2011-12-27 | Cypress Semiconductor Corporation | Differential-to-single ended signal converter circuit and method |
US8085100B2 (en) | 2005-02-04 | 2011-12-27 | Cypress Semiconductor Corporation | Poly-phase frequency synthesis oscillator |
US8089461B2 (en) | 2005-06-23 | 2012-01-03 | Cypress Semiconductor Corporation | Touch wake for electronic devices |
US8092083B2 (en) | 2007-04-17 | 2012-01-10 | Cypress Semiconductor Corporation | Temperature sensor with digital bandgap |
US8103496B1 (en) | 2000-10-26 | 2012-01-24 | Cypress Semicondutor Corporation | Breakpoint control in an in-circuit emulation system |
US8103497B1 (en) | 2002-03-28 | 2012-01-24 | Cypress Semiconductor Corporation | External interface for event architecture |
US8120408B1 (en) | 2005-05-05 | 2012-02-21 | Cypress Semiconductor Corporation | Voltage controlled oscillator delay cell and method |
US8130025B2 (en) | 2007-04-17 | 2012-03-06 | Cypress Semiconductor Corporation | Numerical band gap |
US8149048B1 (en) | 2000-10-26 | 2012-04-03 | Cypress Semiconductor Corporation | Apparatus and method for programmable power management in a programmable analog circuit block |
US8160864B1 (en) | 2000-10-26 | 2012-04-17 | Cypress Semiconductor Corporation | In-circuit emulator and pod synchronized boot |
US8176296B2 (en) | 2000-10-26 | 2012-05-08 | Cypress Semiconductor Corporation | Programmable microcontroller architecture |
US8286125B2 (en) | 2004-08-13 | 2012-10-09 | Cypress Semiconductor Corporation | Model for a hardware device-independent method of defining embedded firmware for programmable systems |
US8402313B1 (en) | 2002-05-01 | 2013-03-19 | Cypress Semiconductor Corporation | Reconfigurable testing system and method |
US8499270B1 (en) | 2007-04-25 | 2013-07-30 | Cypress Semiconductor Corporation | Configuration of programmable IC design elements |
US8516025B2 (en) | 2007-04-17 | 2013-08-20 | Cypress Semiconductor Corporation | Clock driven dynamic datapath chaining |
US8527949B1 (en) | 2001-11-19 | 2013-09-03 | Cypress Semiconductor Corporation | Graphical user interface for dynamically reconfiguring a programmable device |
US9448964B2 (en) | 2009-05-04 | 2016-09-20 | Cypress Semiconductor Corporation | Autonomous control in a programmable system |
US9564902B2 (en) | 2007-04-17 | 2017-02-07 | Cypress Semiconductor Corporation | Dynamically configurable and re-configurable data path |
US9720805B1 (en) | 2007-04-25 | 2017-08-01 | Cypress Semiconductor Corporation | System and method for controlling a target device |
US10698662B2 (en) | 2001-11-15 | 2020-06-30 | Cypress Semiconductor Corporation | System providing automatic source code generation for personalization and parameterization of user modules |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997005679A1 (en) | 1995-07-27 | 1997-02-13 | Jds Fitel Inc. | Method and device for wavelength locking |
JPH10253452A (en) * | 1997-03-07 | 1998-09-25 | Sun Tec Kk | Monitoring device for wavelength of laser beam source |
US5825792A (en) * | 1996-07-11 | 1998-10-20 | Northern Telecom Limited | Wavelength monitoring and control assembly for WDM optical transmission systems |
US6094446A (en) * | 1997-01-21 | 2000-07-25 | Santec Corporation | Wavelength stabilizing apparatus of laser light source |
US6101200A (en) * | 1997-12-24 | 2000-08-08 | Nortel Networks Corporation | Laser module allowing simultaneous wavelength and power control |
US6122301A (en) * | 1998-06-17 | 2000-09-19 | Santec Corporation | Laser light source apparatus |
US6144025A (en) * | 1999-01-13 | 2000-11-07 | Santec Corporation | Laser light source apparatus |
US6198757B1 (en) * | 1998-08-26 | 2001-03-06 | Lucent Technologies Inc. | Control system for wavelength stabilization of a laser source |
-
1999
- 1999-03-09 US US09/265,291 patent/US6384947B1/en not_active Expired - Lifetime
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997005679A1 (en) | 1995-07-27 | 1997-02-13 | Jds Fitel Inc. | Method and device for wavelength locking |
US5825792A (en) * | 1996-07-11 | 1998-10-20 | Northern Telecom Limited | Wavelength monitoring and control assembly for WDM optical transmission systems |
US6094446A (en) * | 1997-01-21 | 2000-07-25 | Santec Corporation | Wavelength stabilizing apparatus of laser light source |
JPH10253452A (en) * | 1997-03-07 | 1998-09-25 | Sun Tec Kk | Monitoring device for wavelength of laser beam source |
US6101200A (en) * | 1997-12-24 | 2000-08-08 | Nortel Networks Corporation | Laser module allowing simultaneous wavelength and power control |
US6122301A (en) * | 1998-06-17 | 2000-09-19 | Santec Corporation | Laser light source apparatus |
US6198757B1 (en) * | 1998-08-26 | 2001-03-06 | Lucent Technologies Inc. | Control system for wavelength stabilization of a laser source |
US6144025A (en) * | 1999-01-13 | 2000-11-07 | Santec Corporation | Laser light source apparatus |
Non-Patent Citations (3)
Title |
---|
B. Villaneuve, H.B. Kim, M. Cyr, and D. Gariepy-A Compact Wavelength Stabilizatin Scheme for Telecommunication Transmittors. |
Santec Product Catalog, OWL-12/20.* * |
Santec Technical Note-Optical Wavelength Locker/Monitor OWL-10. |
Cited By (61)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6469814B1 (en) * | 1998-11-09 | 2002-10-22 | Electronics And Telecommunications Research Institute | Apparatus and method for detecting channel information from WDM optical signal by using wavelength selective photo detector |
US6545788B1 (en) * | 1999-03-09 | 2003-04-08 | Agere Systems, Inc. | Multiple path digital wavelength stabilization |
US6519068B1 (en) * | 1999-10-18 | 2003-02-11 | Agere Systems Inc. | Circuits and methods for achieving high signal-to-noise ratios and obtaining stabilized laser signals in dense wavelength division multiplexing systems |
US8103496B1 (en) | 2000-10-26 | 2012-01-24 | Cypress Semicondutor Corporation | Breakpoint control in an in-circuit emulation system |
US8149048B1 (en) | 2000-10-26 | 2012-04-03 | Cypress Semiconductor Corporation | Apparatus and method for programmable power management in a programmable analog circuit block |
US8358150B1 (en) | 2000-10-26 | 2013-01-22 | Cypress Semiconductor Corporation | Programmable microcontroller architecture(mixed analog/digital) |
US10261932B2 (en) | 2000-10-26 | 2019-04-16 | Cypress Semiconductor Corporation | Microcontroller programmable system on a chip |
US8176296B2 (en) | 2000-10-26 | 2012-05-08 | Cypress Semiconductor Corporation | Programmable microcontroller architecture |
US10248604B2 (en) | 2000-10-26 | 2019-04-02 | Cypress Semiconductor Corporation | Microcontroller programmable system on a chip |
US10020810B2 (en) | 2000-10-26 | 2018-07-10 | Cypress Semiconductor Corporation | PSoC architecture |
US7765095B1 (en) | 2000-10-26 | 2010-07-27 | Cypress Semiconductor Corporation | Conditional branching in an in-circuit emulation system |
US10725954B2 (en) | 2000-10-26 | 2020-07-28 | Monterey Research, Llc | Microcontroller programmable system on a chip |
US8555032B2 (en) | 2000-10-26 | 2013-10-08 | Cypress Semiconductor Corporation | Microcontroller programmable system on a chip with programmable interconnect |
US7825688B1 (en) | 2000-10-26 | 2010-11-02 | Cypress Semiconductor Corporation | Programmable microcontroller architecture(mixed analog/digital) |
US8160864B1 (en) | 2000-10-26 | 2012-04-17 | Cypress Semiconductor Corporation | In-circuit emulator and pod synchronized boot |
US9843327B1 (en) | 2000-10-26 | 2017-12-12 | Cypress Semiconductor Corporation | PSOC architecture |
US9766650B2 (en) | 2000-10-26 | 2017-09-19 | Cypress Semiconductor Corporation | Microcontroller programmable system on a chip with programmable interconnect |
US8736303B2 (en) | 2000-10-26 | 2014-05-27 | Cypress Semiconductor Corporation | PSOC architecture |
US8793635B1 (en) | 2001-10-24 | 2014-07-29 | Cypress Semiconductor Corporation | Techniques for generating microcontroller configuration information |
US8069428B1 (en) | 2001-10-24 | 2011-11-29 | Cypress Semiconductor Corporation | Techniques for generating microcontroller configuration information |
US10466980B2 (en) | 2001-10-24 | 2019-11-05 | Cypress Semiconductor Corporation | Techniques for generating microcontroller configuration information |
US8078970B1 (en) | 2001-11-09 | 2011-12-13 | Cypress Semiconductor Corporation | Graphical user interface with user-selectable list-box |
US7526422B1 (en) | 2001-11-13 | 2009-04-28 | Cypress Semiconductor Corporation | System and a method for checking lock-step consistency between an in circuit emulation and a microcontroller |
US10698662B2 (en) | 2001-11-15 | 2020-06-30 | Cypress Semiconductor Corporation | System providing automatic source code generation for personalization and parameterization of user modules |
US7844437B1 (en) | 2001-11-19 | 2010-11-30 | Cypress Semiconductor Corporation | System and method for performing next placements and pruning of disallowed placements for programming an integrated circuit |
US8370791B2 (en) | 2001-11-19 | 2013-02-05 | Cypress Semiconductor Corporation | System and method for performing next placements and pruning of disallowed placements for programming an integrated circuit |
US8527949B1 (en) | 2001-11-19 | 2013-09-03 | Cypress Semiconductor Corporation | Graphical user interface for dynamically reconfiguring a programmable device |
US8533677B1 (en) | 2001-11-19 | 2013-09-10 | Cypress Semiconductor Corporation | Graphical user interface for dynamically reconfiguring a programmable device |
US8069405B1 (en) * | 2001-11-19 | 2011-11-29 | Cypress Semiconductor Corporation | User interface for efficiently browsing an electronic document using data-driven tabs |
US7774190B1 (en) | 2001-11-19 | 2010-08-10 | Cypress Semiconductor Corporation | Sleep and stall in an in-circuit emulation system |
US7770113B1 (en) | 2001-11-19 | 2010-08-03 | Cypress Semiconductor Corporation | System and method for dynamically generating a configuration datasheet |
US8103497B1 (en) | 2002-03-28 | 2012-01-24 | Cypress Semiconductor Corporation | External interface for event architecture |
US8402313B1 (en) | 2002-05-01 | 2013-03-19 | Cypress Semiconductor Corporation | Reconfigurable testing system and method |
US7761845B1 (en) | 2002-09-09 | 2010-07-20 | Cypress Semiconductor Corporation | Method for parameterizing a user module |
EP1458070A1 (en) | 2003-03-12 | 2004-09-15 | Agilent Technologies Inc. a Delaware Corporation | Optical wavelength control system |
US20040179774A1 (en) * | 2003-03-12 | 2004-09-16 | Franco Delpiano | Optical wavelength control system |
US7085448B2 (en) | 2003-03-12 | 2006-08-01 | Franco Delpiano | Optical wavelength control system |
US7893724B2 (en) | 2004-03-25 | 2011-02-22 | Cypress Semiconductor Corporation | Method and circuit for rapid alignment of signals |
US8069436B2 (en) | 2004-08-13 | 2011-11-29 | Cypress Semiconductor Corporation | Providing hardware independence to automate code generation of processing device firmware |
US8286125B2 (en) | 2004-08-13 | 2012-10-09 | Cypress Semiconductor Corporation | Model for a hardware device-independent method of defining embedded firmware for programmable systems |
US8085100B2 (en) | 2005-02-04 | 2011-12-27 | Cypress Semiconductor Corporation | Poly-phase frequency synthesis oscillator |
US8120408B1 (en) | 2005-05-05 | 2012-02-21 | Cypress Semiconductor Corporation | Voltage controlled oscillator delay cell and method |
US8089461B2 (en) | 2005-06-23 | 2012-01-03 | Cypress Semiconductor Corporation | Touch wake for electronic devices |
US8085067B1 (en) | 2005-12-21 | 2011-12-27 | Cypress Semiconductor Corporation | Differential-to-single ended signal converter circuit and method |
US8717042B1 (en) | 2006-03-27 | 2014-05-06 | Cypress Semiconductor Corporation | Input/output multiplexer bus |
US8067948B2 (en) | 2006-03-27 | 2011-11-29 | Cypress Semiconductor Corporation | Input/output multiplexer bus |
CN100452580C (en) * | 2007-02-09 | 2009-01-14 | 中国科学院上海光学精密机械研究所 | Device for stabling semiconductor laser operation wavelength |
US8026739B2 (en) | 2007-04-17 | 2011-09-27 | Cypress Semiconductor Corporation | System level interconnect with programmable switching |
US8130025B2 (en) | 2007-04-17 | 2012-03-06 | Cypress Semiconductor Corporation | Numerical band gap |
US8092083B2 (en) | 2007-04-17 | 2012-01-10 | Cypress Semiconductor Corporation | Temperature sensor with digital bandgap |
US8476928B1 (en) | 2007-04-17 | 2013-07-02 | Cypress Semiconductor Corporation | System level interconnect with programmable switching |
US9564902B2 (en) | 2007-04-17 | 2017-02-07 | Cypress Semiconductor Corporation | Dynamically configurable and re-configurable data path |
US8040266B2 (en) | 2007-04-17 | 2011-10-18 | Cypress Semiconductor Corporation | Programmable sigma-delta analog-to-digital converter |
US7737724B2 (en) | 2007-04-17 | 2010-06-15 | Cypress Semiconductor Corporation | Universal digital block interconnection and channel routing |
US8516025B2 (en) | 2007-04-17 | 2013-08-20 | Cypress Semiconductor Corporation | Clock driven dynamic datapath chaining |
US8078894B1 (en) | 2007-04-25 | 2011-12-13 | Cypress Semiconductor Corporation | Power management architecture, method and configuration system |
US9720805B1 (en) | 2007-04-25 | 2017-08-01 | Cypress Semiconductor Corporation | System and method for controlling a target device |
US8499270B1 (en) | 2007-04-25 | 2013-07-30 | Cypress Semiconductor Corporation | Configuration of programmable IC design elements |
US8909960B1 (en) | 2007-04-25 | 2014-12-09 | Cypress Semiconductor Corporation | Power management architecture, method and configuration system |
US8049569B1 (en) | 2007-09-05 | 2011-11-01 | Cypress Semiconductor Corporation | Circuit and method for improving the accuracy of a crystal-less oscillator having dual-frequency modes |
US9448964B2 (en) | 2009-05-04 | 2016-09-20 | Cypress Semiconductor Corporation | Autonomous control in a programmable system |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6384947B1 (en) | Two path digital wavelength stabilization | |
US7912380B2 (en) | Optical receiver | |
US5282074A (en) | Optical amplification repeating system | |
JP2004356742A (en) | Signal waveform deterioration compensating apparatus | |
EP0930680B1 (en) | Laser diode optical wavelength control apparatus | |
US7939790B1 (en) | Method and apparatus for controlling the gain of an avalanche photodiode with fluctuations in temperature | |
EP0609018B1 (en) | Apparatus for measuring optical power in an optical receiver or the like | |
US8867579B2 (en) | Semiconductor laser device | |
US6545788B1 (en) | Multiple path digital wavelength stabilization | |
US7012697B2 (en) | Heterodyne based optical spectrum analysis with controlled optical attenuation | |
US6456422B1 (en) | Direct optical FM discriminator | |
RU2146069C1 (en) | Method and erbium-doped optical-fiber amplifier for automatic tracking and filtering of wavelength of optical signal being transmitted | |
JPS59207756A (en) | Optical signal generator | |
US20230417596A1 (en) | Balanced light detector | |
US6449077B1 (en) | Method and apparatus for electrically switching a wavelength control system | |
US6347006B1 (en) | Control for periodic optical filter | |
US5822049A (en) | Optical fiber coupler type wavelength measuring apparatus | |
CA2480603A1 (en) | Improved power supply rejection for high bandwidth transimpedance amplifier circuits (tias) | |
US20020009104A1 (en) | Method of stabilizing the wavelength of lasers and a wavelength monitor | |
US6519068B1 (en) | Circuits and methods for achieving high signal-to-noise ratios and obtaining stabilized laser signals in dense wavelength division multiplexing systems | |
US7176437B2 (en) | Photoelectric conversion apparatus and photoelectric conversion system using the same | |
JP2791550B2 (en) | Optical receiving circuit | |
JPS62239727A (en) | Gain control system for avalanche photodiode | |
US20040120639A1 (en) | Method and device for determining and compensating for the tilting of the spectrum in an optical fiber of a data transmission path | |
JPH06252660A (en) | Optical receiver |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: LUCENT TECHNOLOGIES, INC., NEW JERSEY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ACKERMAN, DAVID ALAN;BROUTIN, SCOTT L.;PLOURDE, JAMES KEVIN;AND OTHERS;REEL/FRAME:009815/0871;SIGNING DATES FROM 19990302 TO 19990304 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
AS | Assignment |
Owner name: AGERE SYSTEMS OPTOELECTRONICS GUARDIAN CORP., PENN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:LUCENT TECHNOLOGIES INC.;REEL/FRAME:024697/0152 Effective date: 20010130 Owner name: AGERE SYSTEMS GUARDIAN CORP., NEW JERSEY Free format text: MERGER;ASSIGNOR:LUCENT TECHNOLOGIES INC.;REEL/FRAME:024697/0171 Effective date: 20010831 Owner name: AGERE SYSTEMS INC., PENNSYLVANIA Free format text: MERGER;ASSIGNOR:AGERE SYSTEMS GUARDIAN CORP.;REEL/FRAME:024697/0176 Effective date: 20010831 |
|
FPAY | Fee payment |
Year of fee payment: 12 |
|
AS | Assignment |
Owner name: DEUTSCHE BANK AG NEW YORK BRANCH, AS COLLATERAL AG Free format text: PATENT SECURITY AGREEMENT;ASSIGNORS:LSI CORPORATION;AGERE SYSTEMS LLC;REEL/FRAME:032856/0031 Effective date: 20140506 |
|
AS | Assignment |
Owner name: AGERE SYSTEMS GUARDIAN CORP., PENNSYLVANIA Free format text: MERGER;ASSIGNOR:AGERE SYSTEMS OPTOELECTRONICS GUARDIAN CORP.;REEL/FRAME:033684/0963 Effective date: 20010823 Owner name: AGERE SYSTEMS INC., PENNSYLVANIA Free format text: MERGER;ASSIGNOR:AGERE SYSTEMS GUARDIAN CORP.;REEL/FRAME:033684/0969 Effective date: 20020822 Owner name: AGERE SYSTEMS LLC, PENNSYLVANIA Free format text: CERTIFICATE OF CONVERSION;ASSIGNOR:AGERE SYSTEMS INC.;REEL/FRAME:033685/0042 Effective date: 20120730 |
|
AS | Assignment |
Owner name: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:AGERE SYSTEMS LLC;REEL/FRAME:035365/0634 Effective date: 20140804 |
|
AS | Assignment |
Owner name: LSI CORPORATION, CALIFORNIA Free format text: TERMINATION AND RELEASE OF SECURITY INTEREST IN PATENT RIGHTS (RELEASES RF 032856-0031);ASSIGNOR:DEUTSCHE BANK AG NEW YORK BRANCH, AS COLLATERAL AGENT;REEL/FRAME:037684/0039 Effective date: 20160201 Owner name: AGERE SYSTEMS LLC, PENNSYLVANIA Free format text: TERMINATION AND RELEASE OF SECURITY INTEREST IN PATENT RIGHTS (RELEASES RF 032856-0031);ASSIGNOR:DEUTSCHE BANK AG NEW YORK BRANCH, AS COLLATERAL AGENT;REEL/FRAME:037684/0039 Effective date: 20160201 |
|
AS | Assignment |
Owner name: BANK OF AMERICA, N.A., AS COLLATERAL AGENT, NORTH CAROLINA Free format text: PATENT SECURITY AGREEMENT;ASSIGNOR:AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.;REEL/FRAME:037808/0001 Effective date: 20160201 Owner name: BANK OF AMERICA, N.A., AS COLLATERAL AGENT, NORTH Free format text: PATENT SECURITY AGREEMENT;ASSIGNOR:AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.;REEL/FRAME:037808/0001 Effective date: 20160201 |
|
AS | Assignment |
Owner name: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD., SINGAPORE Free format text: TERMINATION AND RELEASE OF SECURITY INTEREST IN PATENTS;ASSIGNOR:BANK OF AMERICA, N.A., AS COLLATERAL AGENT;REEL/FRAME:041710/0001 Effective date: 20170119 Owner name: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD Free format text: TERMINATION AND RELEASE OF SECURITY INTEREST IN PATENTS;ASSIGNOR:BANK OF AMERICA, N.A., AS COLLATERAL AGENT;REEL/FRAME:041710/0001 Effective date: 20170119 |
|
AS | Assignment |
Owner name: AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE. LIMITE Free format text: MERGER;ASSIGNOR:AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.;REEL/FRAME:047195/0026 Effective date: 20180509 |
|
AS | Assignment |
Owner name: AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE. LIMITE Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE EFFECTIVE DATE OF MERGER PREVIOUSLY RECORDED ON REEL 047195 FRAME 0026. ASSIGNOR(S) HEREBY CONFIRMS THE MERGER;ASSIGNOR:AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.;REEL/FRAME:047477/0423 Effective date: 20180905 |